Add LANGUAGE pragmas to compiler/ source files

In some cases, the layout of the LANGUAGE/OPTIONS_GHC lines has been
reorganized, while following the convention, to

- place `{-# LANGUAGE #-}` pragmas at the top of the source file, before
  any `{-# OPTIONS_GHC #-}`-lines.

- Moreover, if the list of language extensions fit into a single
  `{-# LANGUAGE ... -#}`-line (shorter than 80 characters), keep it on one
  line. Otherwise split into `{-# LANGUAGE ... -#}`-lines for each
  individual language extension. In both cases, try to keep the
  enumeration alphabetically ordered.
  (The latter layout is preferable as it's more diff-friendly)

While at it, this also replaces obsolete `{-# OPTIONS ... #-}` pragma
occurences by `{-# OPTIONS_GHC ... #-}` pragmas.

1 files changed, 2 insertions, 0 deletions

diff --git a/compiler/cmm/PprCmmDecl.hs b/compiler/cmm/PprCmmDecl.hs
index 354a3d4563..dd80f5cd56 100644
--- a/compiler/cmm/PprCmmDecl.hs
+++ b/compiler/cmm/PprCmmDecl.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE CPP #-}
+
 ----------------------------------------------------------------------------
 --
 -- Pretty-printing of common Cmm types